An Australasian test of the recent African origin theory using the WLH-50 calvarium

This analysis investigates the ancestry of a single modern human specimen f rom Australia, WLH-50 (Thorne et al., in preparation; Webb, 1989). Evaluati ng its ancestry is important to our understanding of modern human origins i n Australasia because the prevailing models of human origins make different predictions for the ancestry of this specimen, and others like it. Some au thors believe in the validity of a complete replacement theory and propose that modern humans in Australasia descended solely from earlier modern huma n populations found in Late Pleistocene Africa and the Levant. These ancest ral modern populations are believed to have completely replaced other archa ic human populations, including the Ngandong hominids of Indonesia. Accordi ng to this recent African origin theory, the archaic humans from Indonesia are classified as Homo erectus, a different evolutionary species that could not have contributed to the ancestry of modern Australasians. Therefore th is theory of complete replacement makes clear predictions concerning the an cestry of the specimen WLH-50. We tested these predictions using two method s: a discriminant analysis of metric data for three samples that are potent ial ancestors of WLH-50 (Ngandong, Late Pleistocene Africans, Levant homini ds from Skhul and Qafzeh) and a pairwise difference analysis of nonmetric d ata for individuals within these samples. The results of these procedures p rovide an unambiguous refutation of a model of complete replacement within this region, and indicate that the Ngandong hominids or a population like t hem may have contributed significantly to the ancestry of WLH-50. We theref ore contend that Ngandong hominids should be classified within the evolutio nary species, Homo sapiens. The Multiregional model of human evolution has the expectation that Australasian ancestry is in all three of thr potential ly ancestral groups and best explains modern Australasian origins. (C) 2000 Academic Press.